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Monday, August 29, 2011

Black Widow

When you garden in the South one must always be mindful of certain insects that can be harmful to humans and pets. Georgia is home to three venomous spiders...the brown recluse, northern black widow and the southern black widow.

This weekend my husband was moving some stack stone rocks to create a new pathway through the side garden. He was about to pick up this rock when he saw this beauty.

Black widow spiders are the largest of the cobweb weaver spiders. They are very common in nature and like dark, small spaces and are often found between rocks, log piles, in dark sheltered spots like the corners of your mailbox or in your propane meter tank.

The female is shiny black or brown-black and sometimes has a row of red spots on top of her abdomen. She has a red hour glass on her underside (which I didn't get a photo of) and is venomous. The females can grow to be 1 1/2" long with its legs extended and this one is certainly that big. The male spider has red spots on its abdomen with white lines radiating out to the sides. The male is NOT venomous.

They belong to the genus Latrodectus which in Greek means "biting in secret". They really only bite in self defense when they accidentally come in contact with humans. Most bites feel like a pin prick which are the spiders fangs injecting a very small amount of highly toxic venom. If you are bitten you will know immediately. The venom works quickly...you will get bad cramps, followed by breathing problems, a high fever and then great pain. A black widow's venom is fifteen times more potent than a rattlesnake. The southern black widow is reported to have the most severe bite. It usually isn't deadly if medical attention is received immediately.

The female spider will mature in about 90 days and live another 180 days. She will lay somewhere around 9 egg sacks in one summer. Each egg sack can contain between 400-900 eggs. They incubate for 20 to 30 days. Like praying mantis, usually only a few survive due to cannibalism. This mother had two egg sacks she was trying to protect.

Black widows typically eat other insects, their favorite being mud-dauber wasps. But they also have enemies. Some parasitic wasps will sting and paralyze the black widow. It is also a favorite of the Praying Mantis.

Fortunately my husband saw this spider before he picked up the rock and was good enough to call me to grab my camera. He knows me too well.

I have never enountered a black widow thankfully. I had a spider bite that became infected and grew quite large in less than 24 hours a few weeks ago. it is still healing. And it wasn't venomous as far as we know. We certainly share our garden with all sorts of creatures. Great pics....

This is a beautiful article on widows, Karen! And beautiful shots too!

I thought I'd complicate the case with male widows. First, strictly speaking, all spiders are venomous except for the cribellate orbweavers (Uloboridae). So the question is whether male widow envenomation is dangerous.

Here's the thing with widow venom. It's a systemic neurotoxin, so it affects the victim's entire nervous system. The more venom injected, the greater the effect, and the larger the victim, the smaller the effect. The danger posed by widow venom is given by the proportion of venom injected to the body size of the victim. Also, a person's physiology and immune response can play a significant factor.

So a child bitten by an adult black widow is in much more trouble than a 250-lb man bitten by the same widow. The elderly and people with immune problems are also at risk for their body's inability to handle the venom.

Male black widows are much smaller than adult females, so they inject much less venom when they bite. The effect of their venom is going to be significantly less than that of an adult female, but not necessarily inconsequential. Technically then, all we know is that envenomation by male widows is not known to be dangerous. The venom is likely identical, and it's still likely a bad idea to be handling them as if their venom weren't dangerous.

Thanks again for sharing the beauty of these spiders! Plug: I just launched a spider microblog/photoblog at SpiderJoe.com

Good thing your husband was paying attention. You know you are a true blogger when anything happens you hear the words....grab the camera. I haven't seen many spiders at all this summer because of the drought. We usually see a lot of interesting webs around our back patio. Great photos by the way.

What a great post but I'm really glad we don't have those where I live! I spent some time in Australia once where there are all sorts of biting venonmous critters and was terrified throughout my entire stay.

Oh dear! I don't want to ever see one of these! I'm pretty sure if I went looking I could find one, but this one here on your post is good enough for me! Thanks Karin,Now I'm scared to go out!! hahahaha!;-0

Welcome to Southern Meadows

At Southern Meadows we garden for wildlife. Located in northeast Georgia in eco-region 231 (Southeasst Mixed Forest Province) / zone 8a on 10 acres of meadow and forest habitat. I’m Karin, gardener, photographer and writer. I hope you enjoy a little taste of Georgia and will come back and visit often. xo!

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The NABA Memorial Day Count (in the United States) will be held May 27-29, 2017. All you need to do is to observe butterflies at one or more of your favorite butterflying localities (such as your own backyard) this coming Memorial Day weekend and note what butterflies you’ve seen. There are no requirements regarding how much time or area you cover. Then go to the NABA web site, www.naba.org, and from there to the Recent Sightings (sightings.naba.org) web page and enter your report, filling in the location, date, and butterflies seen.